As the heat grew it focused in more on his balls than the rest of his groin. It went from a gentle warmth to a more aggressive one as he felt the warmth turn into a more stinging sensation. Dan gasped as it focused more and more. Then he felt the pressure. From inside it felt like his balls were going to burst, the feeling so intense he nearly doubled over.
He continued to gasp and groan at the sensation between his legs. Slowly but surely it began to fade after what felt like forever, leaving him with a new feeling. A feeling of weight netween his legs. When he saw what was there he nearly fainted.
Between his legs now was the same cock as before, but now it was adorned with a pair of grapefruit sized balls. On top of that, the tip of his cock drooled out precum at an astonishing rate. Judging by the pressure in his sack, it was full. Overcome by the need to release his load, Dan gripped his cock and went to work, very quickly crying out in pleasure as he shot rope after rope of fresh cum from massive balls. Only once he was finished did he realize he'd now given his one wall a portion of fresh 'paint'.